It is known that power consumption for driving a conveyor belt changes according to the type of conveyor belt and peripheral equipment such as driving rollers, in addition to being influenced by changes or the like in the weight of transportation articles which are stacked on the conveyor belt. Since the number of support rollers which support the conveyor belt increases when the belt conveyor has a long length, power loss caused by contact between the conveyor belt and the support rollers is predominant in terms of the power consumption. Therefore, reducing the power loss occurring when moving over the support rollers, that is, the resistance to moving over the support rollers, has become an important issue.
When measuring the resistance to moving over support rollers using an actual belt conveyor device, it is necessary to have a large scale measuring device in addition to the actual conveyor belt. Therefore, a high cost is incurred and a long time is required for measurement and evaluation. Therefore, a method and a device for measuring the resistance to moving over a support roller using a cut sample of a conveyor belt as an evaluation subject, have been proposed (refer to Japanese Unexamined Patent Application Publication No. 2006-292736A).
In the technology proposed in Japanese Unexamined Patent Application Publication No. 2006-292736A, the actual conveyor belt is not necessary. In addition, it is possible to reduce the size of the device since the device has a structure so that the support roller is moved and rolled on the surface of the evaluation subject with the evaluation subject provided in a tensioned state and fixed. Therefore, it is possible to reduce the cost and time required for the measurement and evaluation. However, since a device which attaches a load cell to both ends of the evaluation subject and connects the load cell between the both ends in a tensioned state is necessary in this technology and a strain gauge is attached in the form of a cantilever to the rolling surface of the support roller, there is a problem in that the device is complicated. The support roller is given a special structure which is different to the original specifications so as to measure the degree of deformation, in the radial direction, of the outer peripheral surface of the support roller using the strain gauge. Therefore, it is also necessary to consider measurement errors caused by deformation of the outer peripheral surface of the support roller.